“It’s been said that in 20 years or so,” Greg O’Brien writes in a comment on Reddit, “there will be two kinds of people in the world: those with Alzheimer’s and those caring for someone with Alzheimer’s.”

Seven years ago, the journalist was diagnosed with early-onset Alzheimer’s, a disease that claimed relatives on both sides of his family.

Yesterday, the author of On Pluto: Inside the Mind of Alzheimer’s stopped by Reddit for an AMA (Ask Me Anything) to share his perspective on supporting family members with Alzheimer’s and dealing with the diagnosis firsthand, while also bringing attention to PBS’s documentary airing tonight called Can Alzheimer’s Be Stopped?

In his AMA, O’Brien discusses the earliest symptoms he experienced, how recently diagnosed patients can pursue treatment, and what recent medical advances make him the most optimistic.